The present invention relates to vibration damping mechanism for a piston type compressor.
As disclosed in Japanese Unexamined Patent Publication No. 2000-18156, compression reactive force is generated in a piston type compressor in compressing gas by a piston and causes the piston type compressor to vibrate. Namely, the front housing vibrates since the compression reactive force is transmitted to a front housing through a swash plate, a hinge mechanism, a lug plate and a thrust bearing.
In Japanese Unexamined Patent Publication No. 2000-18156, in order to reduce the vibration of the compressor, a vibration damping steel sheet is placed between the front housing and the thrust bearing or between the lug plate and the thrust bearing.
The vibration damping steel sheet is constituted of a pair of steel pieces and rubber bonded between the pair of steels with glue. The adhesion of the glue deteriorates due to a relatively high temperature in the compressor whose maximum temperature is 200° C. Therefore, it is hard to maintain enough adhesive strength of the glue. That is, it is hard to keep the durability of the vibration damping steel sheet. Also, since the vibration absorption performance of rubber or resin depends on temperature and the temperature in the compressor varies, it is hard to maintain the vibration absorption performance of an elastic member that is made of rubber and resin for absorbing a target frequency of the vibration. Furthermore, since the vibration damping steel sheet is bent to correspond with the shape of the inner wall of the front housing, the vibration absorption performance of the vibration damping steel sheet varies depending on the region of the sheet. Therefore, bending the vibration damping steel is not generally desired. That is, the degree of the freedom in the shape of the vibration damping steel sheet is relatively small.
As described above, because of the relatively large load applied to the elastic member and the relatively high temperature up to 200° C. in the compressor, it is hard to maintain the durability of the elastic member made of rubber or resin.